<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .fu{

        }
        .f1_left{
            width:  611px;
            height: 376px;
            float: left;
            background-color: gray;
        }
        .f1_right{
            width: 375px;
            height: 376px;
            float: left;
            background-color: yellow;
        }
    </style>
</head>
<body>
<div class="fu">

    <div class="f1">
        <div class="f1_left"></div>
        <div class="f1_right"></div>
    </div>


    <div class="f2"></div>

</div>

</body>
</html>